1. Field of the Invention
This invention relates to a novel compound with the anti-viral activity and a drug and anti-viral agent containing said compound as th e effective ingredient, more specifically relates to a medicine and anti-HV active compound comprising the sulfated nonulonic acid.
2. Description of the Related Arts
Azidothymidine (AZT) and dideoxy inosine (DDI) have been used as the AIDS remedy. These agents are to inhibit the reverse transcriptase of HIV, bringing about apothanasic effect to patients, while posing problems that the chronic administration of AZT causes myelopathy and that the DDI administration results in side reactions such as acute pancreatitis and peripheral neuropathy. Furthermore, the use of either drug eventually results in the generation of virus resistant to these drugs.
Recently, the sulfated polysaccharide has been expected as a promising AIDS remedy. It is well known that polysulfated compounds such as dextransulfate (I) (Japanese Patent Laid-Open Publication No. Sho63-45233), polyvinyl alcohol sulfate (II) (Antimicrob. Agents Chemother. 34, 134-138 (1990)), oligosaccharide sulfate (Japanese Patent Laid-Open Publication No. Hei2-304025) inhibit the proliferation of HIV. These compounds are produced simply by binding the sulfate group to polysaccharides, oligosaccharides or organic polymeric molecules.
In addition, the sulfated modified cyclodextrin (III) is cyclodextrin to which lipid-soluble groups such as aryl-, alkyl-groups are introduced, and also has the proliferation inhibiting activity against retroviruses, HV in particular (Japanese Patent Laid-Open Publication No. Hei4-136001). 
In addition, as a virucide comprising the sulfated polysaccharide as the active ingredient is disclosed the one using an acyl derivative of a sulfated oligosaccharide glycoside (Japanese Patent Laid-Open Publication No. Hei6-256373).
At first, it was conceived that the virucidic activity of sulfated polysaccharides was due to their reverse transcriptase inhibiting activities, and now it is thought to be due to the interaction between the sulfated polysaccharide and the coat protein gp120 of HIV.
However, since sulfated polysaccharides generally have the inhibitory activity for the blood coagulation system (anticoagulant activity), they have not been accepted as the suitable medicine.
This invention has been developed in view of the above-mentioned problems, aiming at providing the anti-viral compound with a relatively weak anti-blood coagulating activity and a low cytotoxicity, especially the one with the anti-HIV activity.
The present inventors have actively pursued the study to resolve the above-mentioned problems, establishing that the following compounds are useful for attaining the above-described purpose and completing the present invention.
(1) A compound having all hydroxyl groups of the sugar moiety of glycoside comprising monosaccharide-lipid sulfated or the salt thereof, wherein said lipid moiety is bound to the anomeric position of said sugar moiety.
(2) The compound or the salt thereof according to (1), wherein said sugar and lipid moieties are connected by the O-glycosidic linkage or the S-glycosidic linkage.
(3) The compound or the salt thereof according to (2), wherein said lipid is linear, and said linear lipid has a branched structure.
(4) A compound or the salt thereof, wherein all hydroxyl groups of nonuloic acid moiety of the glycoside comprising a monosaccharide-lipid with said lipid bound to the anomeric position of nonuroic acid derivative are sulfated.
(5) A compound or the salt thereof, wherein all hydroxyl groups of sialic acid moiety or KDN moiety of the glycoside comprising a monosaccaride-lipid with said lipid bound to the anomeric position of sialic acid or KDN are sulfated.
(6) The compounds or the salts thereof according to (5), wherein the binding of said sialic acid moiety or KDN moiety to the lipid moiety is either the O-glycosidic of S-glycosidic linkage at position 2 of said moiety or the amidic linkage at position 1 of said residue.
(7) The compound or the salt thereof according to (6), wherein said lipid is a linear lipid, and this lipid has a branched structure.
(8) The compound or the salt thereof according to (7), wherein said branched chain is localized at position 2 of the main chain of said lipid moiety.
(9) The compound or the salt thereof according to (8), wherein said lipid moiety has a forked two chain structure due to said branching.
(10) The compound or the salt thereof according to (9), wherein said lipid moiety has an alkyl group with the skeleton-forming carbon atoms from 1 to 4 at said branching site.
(11) The compound or the salt thereof according to (9) or (10), wherein the total number of said lipid skeleton-forming atoms is from 22 to 60.
(12) The compound or the salt thereof according to (11), wherein said branched chain comprises a carbon-carbon unsaturated bond.
(13) The compound or the salt thereof according to (11), wherein said branched chain is linear.
(14) The compound or the salt thereof according to (11), wherein said branched chain has an ester linkage or ether linkage, respectively.
(15) The compound or the salt thereof according to (14), wherein said ester linkage or ether linkage is localized at positions 1 or 2 of said branched chain.
(16) The compound or the salt thereof according to (11), wherein the number of skeleton-forming atoms is from 10 to 28 per one branched chain.
(17) The compound or the salt thereof according to (16), wherein the number of skeleton-forming atoms is from 18 to 26 per one branched chain.
(18) The compound or the salt thereof according to (17), wherein the number of skeleton-forming atoms is from 24 per one branched chain.
(19) The compound or the salt thereof according to (18), wherein said forked branched chains are of the same length, respectively.
(20) The compound or the salt thereof according to (19), wherein said forked branched chains are of the same, respectively.
(21) The compound or the salt thereof according to (20), wherein said branched chain has the ester bond or the ether linkage at its position 1 or 2.
(22) The compound or the salt thereof according to (21), wherein said branched chain is linear.
(23) A medicine comprising the compound according to anyone of (1) to (3) in a pharmaceutically effective dosage.
(24) An antiviral drug containing the compound according to anyone of (1) to (3) in a pharmaceutically effective dose.
(25) An anti-HIV drug containing the compound according to anyone of (1) to (3) in a pharmaceutically effective dose.
(26) A drug containing the compound according to anyone of (1) to (21) in a pharmaceutically effective dose.
(27) An antiviral drug containing the compound according to anyone of (1) to (21) in a pharmaceutically effective dose.
(28) An anti-HIV drug containing the compound according to anyone of (1) to
(21) in a pharmaceutically effective dose.
Drugs (23 and 26), furthermore, antiviral drugs (24 and 27), especially anti-HIV drugs (24 and 27) containing compounds according to any one of the above-described (1) to (22) are within the scope of the present invention. However, since drugs, anti-viral drugs and anti-HIV drugs containing the compounds according to any one of the above-described (5) to (22) in pharmaceutically effective doses have lower anti-coagulant activity as well as lower biological toxicity than those containing compounds according to any one of the above-described (1) to (3), the former group of drugs are pharmaceutically useful. It has been confirmed that, of the above-described compounds, particularly, those having 24 skeleton-forming atoms per one branched chain (24), furthermore, each of said branched chains of which has the same structure, is linear and has the ether bond at its position 1 or 2, are pharmaceutically useful (examples 12, 13, 29, 50 and 59).
Definition of the Terms
As used in this specification, by the term xe2x80x9cnonuloic acidxe2x80x9d is meant the same nonuloic acid as used generally, an acidic carbohydrate having a carboxyl group at its position 1 and 9 carbon atoms. Accordingly, xe2x80x9cnonuloic acid derivativesxe2x80x9d used in this specification include neuraminic acid (5-amino-3,5-dideoxy-D-glycero-D-galacto-nonuloic acid) and neuraminic acid derivatives. Since the later-described xe2x80x9csialic acidxe2x80x9d is an acyl derivative of neuraminic acid, it is also included in xe2x80x9cnonuloic acid derivativesxe2x80x9d.
By xe2x80x9cKDNxe2x80x9d used in this specification is meant 2-keto-3-deoxy-D-glycero-2-nononic acid. And, by xe2x80x9csialic acid used in this specification is meant the generic name for a series of derivatives of substances having the neuraminic acid as the basic structure (Yasuo Inoue, Seitai Bunsi no Kagaku, Tositu no Kagaku (Chemistry of Biomolecules 1, Chemistry of Carbohydrates), p80-81, Baifukan), and acyl derivatives, more specifically, such as N-acetylneuramic acid and N-glycolylneuramic acid are also included therein.
By xe2x80x9cforked two chainsxe2x80x9d (for example, (9)) is meant a structure constructed with two chains having more than 7 skeleton-forming atoms. Accordingly, alkyl groups according to (10), wherein the total number of their skeleton-forming atoms is 1 to 4, are not included in xe2x80x9cchainxe2x80x9d constructing xe2x80x9cforked two chainsxe2x80x9d.
By xe2x80x9cskeleton-forming atomsxe2x80x9d is meant atoms constructing the skeleton of the chain, including carbon atom, oxygen atom, nitrogen atom, sulfur atom, etc. However, monovalent atom, such as hydrogen atom, is not included in the xe2x80x9cskeleton-forming atomsxe2x80x9d, because it cannot construct the skeleton portion of the chain.
By xe2x80x9csaltxe2x80x9d is meant the sodium and potassium salts which are required to neutralize the intramolecular carboxylic acid and sulfonic acid, to which cations bind so as not to decrease the biological activity. As to the cations bound to said acids, any cations which do not lower the biological activity of the compounds related to the present invention may be used.
Sugars
In principle, the compound related to this invention is a glycosidic compound and the salt thereof comprising a sugar-lipid with said lipid bound to the anomeric carbon of said sugar, wherein hydroxyl groups of said sugar moiety are all sulfated, having an excellent anti-retroviral activity (the above-described (1)). Although there have been hitherto found the sulfated sugars with the anti-retroviral activity, the glycoside comprising a sugar-lipid with sulfate group introduced and having the anti-retroviral activity has not been discovered. In this respect, this invention is valuable in finding that a glycoside comprising a sugar-lipid with the sulfate groups fully (100%) introduced or the derivative thereof has an excellent anti-viral activity.
When the sugar moiety of said glycoside is sialic acid or KDN, the glycoside not only has the strong anti-viral activity, but also lower cytotoxicity, and can preferably achieve the main purpose as medicine (the above-described (5) to (22), (26) to (28)). And, in this case, the hydroxyl groups of the sugar moiety of the compound related to the present invention to be all sulfated to form the wholly sulfated nonulonic acid (the above-described (4)) are at positions 4, 7, 8 and 9 when nonulonic acid is N-acetylneuramic acid, and the glycolyl hydroxyl group at position 5, in addition to the hydroxyl groups at the positions 4, 7, 8 and 9. In the case wherein nonulonic acid is KDN, all the hydroxyl groups at positions 4, 5, 7, 8 and 9 are sulfated.
The bond between the monosaccharide moiety and lipid moiety of the compound related to the present invention can be of any type. Accordingly, the bond between the monosaccharide and lipid may be not only the O-glycosidic linkage but also S-glycosidic linkage. Furthermore, in the case where the sugar moiety of the compound related to the present invention is nonuloic acid, the amide linkage and ester linkage can be formed using the carboxyl group at position 1, in addition to a glycosidic linkage with the carbon atom at position 2. The bond between monosaccharide and lipid in the compound related to the present invention can be such amide linkage and ester linkage. Therefore, although, by xe2x80x9cglycosidexe2x80x9d is generally meant a compound wherein the monosaccharide and lipid moieties are linked by a glycosidic linkage, by xe2x80x9cglycosidexe2x80x9d in this specification is meant a compound wherein the monosaccharide and lipid are bonded not only in a glycosidic linkage but also in amide and ester linkages. Accordingly, not only compounds having a glycosidic linkage at position 1 of monosaccharide such as glucose or position 2 of nonulonic acid but also those having an amide linkage or ester linkage at position 1 of nonulonic acid are also in the scope of xe2x80x9cglycosidexe2x80x9d of the present invention. Therefore, although, by xe2x80x9cglycosidexe2x80x9d is generally meant a compound wherein the monosaccharide and lipid moieties are linked by a glycosidic linkage, by xe2x80x9cglycosidexe2x80x9d in this specification is meant a compound wherein the monosacchharide and lipid are bonded not only in a glycosidic linkage but also in amide and ester linkages. Accordingly, not only compounds having a glycosidic linkage at position 1 of monosaccharide such as glucose or position 2 of nonulonic acid but also those having an amide linkage or ester linkage at position 1 of nonulonic acid are also in the scope of xe2x80x9cglycosidexe2x80x9d of the present invention.
However, in consideration of the overall manufacturing easiness and biological activity of these compounds, glycosides with the O-glycosidic, S-glycosidic, and amide linkages are preferred.
Lipids
By xe2x80x9clipidxe2x80x9d in the compound related to this invention is meant the lipid in a broad sense including steroid, carotinoid, terpenoid, etc., and conceptually even the compound such as cholesterol. However, the compound related to this invention is preferably a linear lipid, which further preferably has the branched chain structure (the above-described (7)). The branch can be two-forked or three-forked, located at position 2 of the main chain of the lipid moiety. As a result, the lipid is preferably two-forked at the xcex2 position (xcex2 position with respect to the sugar moiety) of said lipid moiety (the above-described (8) and (9)). Furthermore, this branching site may have alkyl group with the skeleton-forming atoms 1 to 4 (the above-described (10)). xe2x80x9cAlkyl group with the skeleton-forming atoms 1 to 4xe2x80x9d herein cited includes, for example, methyl group, ethyl group, propyl group, etc.
The above-described two-forked chain can be a hydrocarbon chain, which can include heteroatoms such as oxygen, nitrogen, sulfur, etc. Furthermore, regardless of the species of component atoms, the total number of the skeleton-forming atoms of lipid is preferably 22 to 60 (the above-described (11)). In addition, the above-described two-forked chains can have unsaturated bond between carbon atoms, respectively (the above-described (12)). Also, although the above-described two-forked chain can be further branched, they are preferably linear (the above-described (13)).
In the case where the above-described two-forked chain contains heteroatoms as the component atom, each branched chain preferably contains an ester bond or ether bond (the above-described (14)), furthermore, said ester bond or ether bond is preferably localized at position 1 or 2 of said branched chain (the above-described (15)).
Herein, when the ester bond or ether bond is present at position 1 of the branched chain, the compound related to this invention will become the sulfated derivative of sialoglycerolipid with the excellent anti-retroviral activity (In this connection, in the case of ether bond present, said compound will be an alkyl glycerol wherein a long-chain alcohol is linked to the glycerol residue, and in the case of ester bond present, said compound will be amyl glycerol.). Furthermore, in the case where ester bond or ether bond is located at position 2 of the branched chain, the glycerol residue in the glycerol area is suitably modified to become pseud-glycerol.
As to the length of branched chains, the number of skeleton-forming atom is preferably 10 to 28 (the above-described (18)), more preferably 18 to 26 (the above-described (17)), most preferably 24 (the above-described (18)). In addition, forked-chains can be of different lengths, but preferably of the same length (the above-described (19)), most preferably of the same structure comprised of the same component atoms (the above-described (20)).
Method of Administration
When compounds related to the present invention are used as therapeutics, they are administered singly or in combination with pharmaceutically acceptable medical carriers, either organic or inorganic and either solid or liquid. Their compositions are determined according to the solubility, chemical property, administration route and schedule of compounds.
Compounds related to this invention can be administered by any suitable desired administration routes. More specifically, compounds related to this invention can be administered intraperitoneally, subcutaneously, percutaneously, intravenously or intra-arterially, and locally injected in the case of animals, and intravenously, intra-arterially, by local injection, intraperitoneally/intrapleurally, orally, subcutaneously, intramuscularly, sublingually, percutaneously, inhalationally or rectally in the case of humans.
Dosage form
When compounds related to the present invention are administered as the drug, they can be administered, according to the method and purpose of their administration, in the form of injection, suspension, tablet, granule, powder, capsule, ointment, cream, suppository, tape, etc. For preparing these drugs, solvent, solubilizing agent, isotonizing agent, preservative, anti-oxidant, excipient, binder, lubricant, stabilizer, etc. can be added.
Solvents are exemplified, for example, by water, physiological sodium chloride solution, etc.; solubilizing agents, for example, by ethanol, polysorbates, chromophore, etc.; excipients, for example, by lactic acid, sucrose, starch, cellulose, crystalline cellulose, dextrin, mannitol, maltose, kaolin, calcium hydrogenphosphate, light anhydrous silicic acid, calcium carbonate, etc.; binders, for example, by starch, polyvinylpyrrolidone, hydroxypropyl cellulose, ethyl cellulose, carboxymethyl cellulose, gum arabic, etc.; disintegrators, for example, by starch, calcium carboxymethyl cellulose, etc.; lubricants, for example, by magnesium stearate, talc, hydrogenated oil, etc.; stabilizers, for example, by lactose, mannitol, maltose, polysorbates, macrogols, polyoxyethylene hydrogenated castor oil, etc. Furthermore, glycerol, dimethylacetamide, 70% sodium lactate, surfactant, basic substances (such as sodium hydroxide, ethylenediamine, ethanolamine, sodium carbonate, arginine, meglumine, tris-aminomethane) may be added, if needed. Using these components, compounds related to this invention can be prepared to the dosage forms such as injections, tablets, granules, capsules, etc.
Compounds related to this invention can be administered orally in dosage forms such as granule, fine granule, powder, tablet, heavy syrup, soft capsule, syrup, emulsion, suspension, liposome, liquid preparation, etc. Liquid preparations such as emulsion, syrup, suspension, liquid drug, etc. for oral administration comprise generally used inert diluents, for example, water or vegetable oil. These preparations can also include supplements, for example, moistening agents, suspending agents, sweetening agents, aromatics, coloring matters, preservatives, etc., in addition to these inert diluents. Liquid preparations may be enveloped in capsules made of absorbable materials such as gelatin.
For administration by intravenous, intramuscular and subcutaneous injections, compounds may be made in powder form for injection, and prepared for injection prior to use. Solvents or suspending agents for preparing drugs for parenteral administration, that is, injections, etc. are exemplified, for example, by water, propylene glycol, polyethylene glycol, benzylalcohol, ethyl oleate, lecithin, etc. Preparation of pharmaceutics can be carried out according to the conventional method.
Treatment
It is desirable that clinical dosages are appropriately increased and/or decreased according to the age, symptom, presence or absence of simultaneous administration of other drugs. The daily dosage of compounds related to this invention may be administered once daily, or in two or three divided portions at appropriate intervals, or intermittently. In view of results of animal experiments and various conditions, dosages of compounds related to this invention are determined such that the total dosage does not exceed a certain limit regardless of whether they are administered once or repeatedly. Needless to say that the optimum dosage is varied according to the method of administration, conditions of patients or animals to be treated such as age, body weight, sex, susceptibility, food (diet), time of administration, drugs in joint use, patient""s conditions, severity of symptoms, etc. In addition, the optimal dosage and administration frequency under the certain conditions must be determined by the suitable usage determination test performed by a medical specialist according to the above-describe guideline.